LANSING, MI - U.S. Rep. John Dingell, with gavel in hand, presided over the passage of Medicare 47 years ago.

Now the Michigan Democrat is attacking GOP proposals to move those under 55 to a voucher system when they hit Medicare age.

"The Romney-Ryan budget ends Medicare as we know it. It puts millions of seniors across the country at risk," Dingell told reporters Friday in a conference call arranged by President Barack Obama's re-election campaign.

He cited a report that moving to a voucher system would increase costs by $6,400 a year on the average Medicare participant. He also estimated Ryan's plan to cut federal spending on Medicaid would leave 429,000 to 831,000 low-income or disabled Michigan residents without health insurance.

He said another 473,000 would be denied the opportunity for Medicaid coverage if the Affordable Care Act is repealed - a goal of Romney and Ryan's.

"I remember the difficulty senior citizens and aging Americans had not only getting health care but qualifying for it," Dingell said of the days before Medicare.

Medicare's hospital insurance fund is projected to become insolvent in 2024.

Asked by MLive what Democrats would do to shore up Medicare as an alternative to the Ryan plan, Dingell stressed that 2024 is the worst-case scenario for when it starts operating in the red. He said Medicare could still meet most of its obligations for a "fairly good period" after 2024.

To fix Medicare, he said, Democrats need to hold onto the White House and Senate and retake control of the House.

The solution?

A combination of increased revenue, reduced benefit levels and a crackdown on waste and fraud, he said. He did not elaborate on how more revenue could be raised but said it could be "fairly easily done without a particular hurt to anyone."

Matt McGrath, spokesman for the Obama campaign in Michigan, said the Democratic-backed Affordable Care Act strengthened Medicare by extending the insolvency date from 2016 to 2024 - thanks in part to more than $700 billion in savings now criticized by the Romney ticket.

The Republican National Committee, meanwhile, started a countdown clock blaming Obama for not doing enough to fix Medicare before it runs into insolvency problems.